<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        b {
            padding: 10px;
            margin: 10px;
            background-color: #fcc;
        }
        
        .on {
            background-color: #09f;
        }
    </style>
</head>

<body>
    <div id="app">
        <img v-for='(item,index) in list' :src="item" v-show='activeIndex==index'>
        <p>
            <b v-for='(item,index) in list' @click='activeIndex=index' :class="activeIndex==index?'on':''">{{index}}</b>
        </p>
    </div>
    <script src="./vue.js"></script>
    <script>
        const vue = new Vue({
            el: '#app',
            data: {
                activeIndex: 0,
                list: ['./img/pic_1.jpg', './img/pic_2.jpg', './img/pic_3.jpg', './img/pic_4.jpg']
            }
        })
    </script>
</body>

</html>